Previously I reviewed one of the only books ever published on real airship design.
The author Charles P. Burgess worked for the National Advisory Committee for Aeronautics, the NACA.

During the heyday of the great rigid airships, in the first third of the 20th century, the NACA commissioned and collected a series of technical studies, papers and technological reviews of airship design. These papers show just how seriously rigid airships were taken as the future of heavy lift and long distance aircraft.

Recently NASA (the direct descendant of the NACA) has made scans of these reports and analyses available through the Internet Archive.

Here you will find yellowed type written reports, with hand drawn graphs, diagrams, plans, and old photographs, documenting in detailed analyses the state of the art in Airship design in 20's and 30's.

The files are available in many formats including plain text, colour PDFs, html, epub and other ebook formats.

Many of these reports are translations of German reports. The Germans were the acknowledged world leaders in Airship design at the time. The first report listed includes a German paper written in 1933 while the Hindenburg was under construction and before the loss of the Akron, which is noted in a footnote. The full report was not translated and acquired by the NACA till 1938.

Since these reports were typewritten they often contain typos, to me these little errors bring these fairly dry technical reports alive. In a way they show them as being human made. Prepared to record important information not just display elegant formatting.

For anyone interested in the technical details of real airship designs these reports are truly a gold mine of information.